KR101574913B1 - Carbon nanofiber aggregate, thermoplastic resin composition, and process for producing thermoplastic resin composition - Google Patents

Abstract

To provide a carbon nanofiber aggregate which is capable of suppressing scattering and which is excellent in dispersibility and filling property with respect to a thermoplastic resin.
The maximum pore volume P1 (cm3 / g) at a pore diameter of not less than 2,500 nm and not more than 100,000 nm and the maximum pore volume P2 (cm3 / g) at a pore diameter of not less than 6 nm and less than 2,500 nm in pore distribution data measured by mercury porosimetry (Cm < 3 > / g) satisfy a specific relationship.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carbon nanofiber aggregate, a thermoplastic resin composition, and a method for producing the thermoplastic resin composition. BACKGROUND ART Carbon nanofiber agglomerates, thermoplastic resin compositions,

The present invention relates to a carbon nanofiber aggregate, a thermoplastic resin composition containing the same, and a method for producing the thermoplastic resin composition.

Carbon nanofibers are considered to be made of a composite material of high performance by being combined with a thermoplastic resin. For example, attempts have been made to assemble carbon nanofibers for the purpose of increasing the bulk density of carbon nanofibers (for example, Patent Documents 1 to 8, etc.).

Japanese Unexamined Patent Publication No. Hei 01-270543 JP-A-03-056566 Japanese Patent Application Laid-Open No. 2005-239531 Japanese Patent Application Laid-Open No. 2006-143532 Japanese Laid-Open Patent Publication No. 2009-184849 Japanese Laid-Open Patent Publication No. 2010-043169 International Publication No. 2009/008516 pamphlet Japanese Laid-Open Patent Publication No. 2011-084844

However, since the carbon nanofibers have a low bulk density and a large amount of air contained per unit volume, there is a problem that they are not uniformly mixed with the pellets or powders of the thermoplastic resin. For example, in the case of extruding the carbon nanofibers and the thermoplastic resin, it is necessary to separate the carbon nanofibers and the thermoplastic resin from each other and to bring them into contact with the thermoplastic resin at a higher pressure than usual, And the problem that it can not be increased. In addition, since the carbon nanofibers have a low bulk density, they are liable to be scattered and difficult to handle. As described above, the conventional carbon nanofiber assemblies have not yet been sufficiently studied for suppressing scattering and improving the dispersibility and filling property with respect to the thermoplastic resin.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a carbon nanofiber aggregate capable of suppressing scattering and excellent in dispersibility and filling property with respect to a thermoplastic resin, and a resin composition containing the same.

As a result of intensive studies to solve the above problems, the present inventors have found that, in the pore distribution data measured with a mercury porosimeter, the maximum pore volume P1 (pore diameter) at a pore diameter of from 2,500 nm to 100,000 nm Cm 3 / g) and the maximum pore volume P 2 (cm 3 / g) at a pore diameter of 6 nm or more and less than 2,500 nm.

That is, the present invention is as follows.

[One]

The maximum pore volume P1 (cm3 / g) at a pore diameter of not less than 2,500 nm and not more than 100,000 nm and the maximum pore volume P2 (cm3 / g) at a pore diameter of not less than 6 nm and less than 2,500 nm in pore distribution data measured by mercury porosimetry (Cm < 3 > / g) satisfy the relations of the following formulas (1) and (2).

0.01? P1? 1 (1)

0 < P1 / P2? 3.3 (2)

[2]

The aggregate of carbon nanofibers according to [1], wherein the carbon nanofiber aggregate has a three-dimensionally assembled structure as the intergranular structure of the carbon nanofibers constituting the aggregate of carbon nanofibers.

[3]

Wherein the pore distribution data measured by the mercury porosimeter includes a cumulative pore volume Q1 (cm3 / g) at a pore diameter of from 2,500 to 100,000 nm and a cumulative pore volume at a pore diameter of from 6 to 2500 nm The aggregate of carbon nanofibers according to [1] or [2], wherein Q2 (cm3 / g) satisfies the relationship of the following formula (3).

0.75? Q2 / (Q1 + Q2) <1 (3)

[4]

(A) at least one member selected from the group consisting of carbon nanofibers, (B) a modified rosin, a styrene resin, an olefin resin, and an acrylic acid resin,

The carbon fiber according to any one of [1] to [3], wherein the content of the carbon nanofiber aggregate having a particle size passing through a sieve having a nominal scale size defined by JIS Z8801-1 of not less than 0.3 mm but not more than 4.75 mm is 90% Nanofiber aggregates.

[5]

100 parts by mass of the component (A)

0.1 to 50 parts by mass of the component (B)

(C) 0.01 to 30 parts by mass of a surfactant

Carbon nanofiber aggregate according to &lt; RTI ID = 0.0 &gt; [4]. &Lt; / RTI &gt;

[6]

The aggregate of carbon nanofibers according to [4] or [5], wherein the content of the component (B) relative to 100 parts by mass of the component (A) is 0.1 to 40 parts by mass.

[7]

A thermoplastic resin composition comprising a thermoplastic resin and the carbon nanofiber aggregate according to any one of [1] to [6].

[8]

The thermoplastic resin composition according to [7], wherein the L / D ratio of the carbon nanofibers in the thermoplastic resin composition is 50 or more.

[9]

10 pellets molded from the above thermoplastic resin composition were cut out by a microtome into pellets and observed with a light microscope (400 times) at a viewing angle of 200 占 퐉 占 200 占 퐉, the carbon observed in the observation region of the optical microscope The thermoplastic resin composition according to [8], wherein the long axis of the nanofiber aggregate is all less than 10 μm.

[10]

A process for producing a thermoplastic resin composition comprising a thermoplastic resin and a step of melt-kneading the carbon nanofiber aggregate according to any one of [1] to [6] to obtain a thermoplastic resin composition.

According to the present invention, it is possible to provide a carbon nanofiber aggregate which can suppress scattering and is excellent in dispersibility and filling property with respect to a thermoplastic resin.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a conceptual diagram for explaining a coagulation structure of a preferable example of the carbon nanofiber aggregate of the present embodiment. Fig.
Fig. 2 is a conceptual diagram for explaining a coagulation structure of another example of a preferable example of the carbon nanofiber aggregate of the present embodiment.
3 is a graph showing a mercury porosimeter measurement result of the raw material carbon nanofiber and the carbon nanofiber agglomerate in Example 7. Fig.

Hereinafter, a mode for carrying out the present invention (hereinafter simply referred to as &quot; present embodiment &quot;) will be described in detail. The following embodiments are illustrative of the present invention and are not intended to limit the present invention to the following contents. The present invention can be appropriately modified within the scope of the gist of the invention.

The aggregate of carbon nanofibers of the present embodiment is characterized in that, in the pore distribution data measured by a mercury porosimeter, the maximum pore volume P1 (cm3 / g) at a pore diameter of from 2,500 to 100,000 nm, (Cm &lt; 3 &gt; / g) of the carbon nanofibers in the carbon nanofibers satisfies the relations of the following formulas (1) and (2)

0.01? P1? 1 (1)

0 &lt; P1 / P2? 3.3 (2)

The present inventors have studied extensively in order to improve the dispersibility and the like in the thermoplastic resin. At that time, not only the macroscopic structure of the carbon nanofiber agglomerates but also the micro structure was studied, and it was surprisingly found that the control of the pore structure composed of the mercury porosimeter measurement was effective in improving the dispersibility I got it. As a result of extensive studies, it has been found that the above-mentioned P1 and P2 are controlled so as to have a pore structure satisfying the relations of the formulas (1) and (2), whereby the carbon nanofiber aggregates are excellent in dispersibility and packing .

The reason is not clear, but it is estimated as follows. When the carbon nanofiber agglomerates and the thermoplastic resin are melt-kneaded by taking the pore structure in which P1 and P2 satisfy the relations of the formulas (1) and (2), the fibers are dispersed in the thermoplastic resin . Further, by applying the shearing force generated at the time of melt kneading, not only the dispersibility is excellent, but also the carbon nanofiber agglomerates can be highly charged to the thermoplastic resin. Moreover, it is also possible to prevent the carbon nanofibers of the carbon nanofiber agglomerates from being broken when the melt-kneading is carried out, and to shorten the length of the carbon nanofibers. Moreover, since the carbon nanofiber agglomerate can be made into a highly filled composite material with good dispersibility, it is expected that various physical properties of the composite material can be improved depending on the application (however, But are not limited thereto).

The intergranular structure of the carbon nanofibers constituting the aggregate of carbon nanofibers of the present embodiment preferably has a three-dimensionally assembled structure. The three-dimensionally assembled structure referred to herein is a structure (secondary aggregation structure) of secondary aggregates assembled by contacting or assimilating a plurality of primary aggregates (an intergranular structure of carbon nanofibers one by one) described later, and And a higher order aggregation structure such as a structure of a tertiary aggregate (tertiary aggregation structure) further aggregated by a plurality of secondary aggregates. The dispersion state of the carbon nanofibers of the present embodiment can be observed also by the measurement method described in the following embodiments.

Further, in the pore distribution data obtained by measuring the carbon nanofiber agglomerates with a mercury porosimeter, the pore volume Q1 (cm3 / g) at pore diameters of 2,500 to 100,000 nm and the pore diameter of 6 nm or more and less than 2,500 nm (Cm &lt; 3 &gt; / g) satisfies the relationship of the following formula (3).

0.75? Q2 / (Q1 + Q2) <1 (3)

The integral pore volume referred to herein refers to the integrated value of the volume of each pore diameter region of the pore distribution measured by the mercury porosimeter. The cumulative pore volumes Q ₁ and Q ₂ can be obtained by the methods described in the following examples.

Here, the case where the cumulative pore volumes Q1 and Q2 satisfy the relation of the above-mentioned formula (3) will be described with reference to Fig. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a conceptual diagram for explaining a coagulation structure of a preferable example of the carbon nanofiber aggregate of the present embodiment. Fig. Fig. 1 is a view schematically illustrating an example of a coagulation structure of a preferred embodiment, and needless to say that the coagulation structure of the carbon nanofiber aggregate of the present embodiment is not limited to the contents shown in the drawings. It is considered that the integrated pore volume Q1 at the pore diameters of 2,500 to 100,000 nm in the carbon nanofiber agglomerates corresponds to a large pore formed between the tertiary agglomerates shown in Fig. The total pore volume Q2 at a pore diameter of 6 nm or more and less than 2,500 nm is obtained by (i) pores inside the primary aggregate formed by collapsing each single fiber, (ii) a secondary aggregate composed of a plurality of primary aggregates , And (iii) the secondary aggregate is composed of a plurality of aggregates. When the carbon nanofiber aggregate and the thermoplastic resin are melt-kneaded by controlling the cumulative pore volumes Q1 and Q2 so as to satisfy the relationship of the formula (3), (i) voids in the primary aggregate, (ii) The molten resin can also penetrate into fine voids such as voids and the like in the inside of the honeycomb structure, and the dispersibility can be further improved. Conventionally, no micro-structure control such as the integrated pore volume has been studied, and from this point of view, it is considered that various improvements in physical properties including excellent dispersibility that are not available in the present embodiment can be achieved (however, The action of the present embodiment is not limited to these).

Further, when Q1 and Q2 satisfy the relation of the formula (3), the conductivity of the carbon nanofiber aggregate is further excellent. From the viewpoint of such carbon nanofiber agglomerates, the average fiber diameter of the carbon nanofibers to be the raw material is preferably 30 nm or less, and more preferably 15 nm or less.

The average fiber diameter of the carbon nanofibers constituting the carbon nanofiber aggregates of the present embodiment is usually from 1 nm to 500 nm, preferably from 5 nm to 200 nm, and more preferably from 8 nm to 150 nm. By setting the lower limit of the average fiber diameter to the above value, the dispersibility of the carbon nanofiber aggregate can be further improved. By setting the upper limit of the average fiber diameter to the above value, the mechanical properties of the thermoplastic resin composition can be further improved. The average fiber diameter is measured by a scanning electron microscope.

The average fiber length of the carbon nanofibers constituting the carbon nanofiber agglomerates of the present embodiment is usually from several tens nm to several thousands of 탆, preferably from 0.5 탆 to 500 탆, and more preferably from 1 탆 to 100 탆. By setting the lower limit of the average fiber length to the above value, the mechanical properties and conductivity of the thermoplastic resin composition can be further improved. By setting the upper limit of the average fiber length to the above value, the dispersibility of the carbon nanofibers of the thermoplastic resin composition can be further improved.

The carbon nanofiber agglomerates of the present embodiment preferably include at least one kind selected from the group consisting of (A) carbon nanofiber, (B) modified rosin, styrene resin, olefin resin, and acrylic acid resin . As a method for producing such a carbon nanofiber aggregate, it is preferable to wet-mix the component (B) in the powdery carbon nanofiber and then dry it. According to this method, it is easy to produce a specific pore structure with respect to the entanglement of the carbon nanofibers.

Here, the aggregation structure of the carbon nanofiber aggregates containing the component (B) will be described with reference to Fig. Fig. 2 is a conceptual diagram for explaining a coagulation structure of another example of a preferable example of the carbon nanofiber aggregate of the present embodiment. Fig. 2 schematically illustrates an example of a cohesive structure of a preferred embodiment. Needless to say, the cohesive structure of the carbon nanofiber aggregate of the present embodiment is not limited to the illustrated contents. In Fig. 2, since the tertiary aggregates are more strongly connected by the component (B), the specific aggregation structure as described in Fig. 1 and the like can be further firmly maintained. In addition, the component (B) is disposed only at the boundary of the tertiary aggregate and is not contained in fine voids or the like, so that the component (B) is prevented from entering into the micropore such as (i) voids inside the primary aggregate, , The molten resin can enter a higher charge-discharge rate. As a result, it is estimated that the dispersibility can be further improved (however, the action of this embodiment is not limited to these).

As described above, it is presumed that the organic matter such as the component (B) plays a role of binding the carbon nanofibers together by chemical bonding or physical bonding. From this point of view, as the component (B), it is preferable not to use a compound which forms a covalent bond with the component (A) in the ends of the molecular chain. For example, as the component (B), it is preferable that substantially no peroxide or azo compound is present at both ends of the molecular chain.

The modified rosin is not particularly limited and, for example, one obtained by reacting at least one rosin selected from the group consisting of tolysine, gum rosin, and wood rosin with a modifying agent. Examples of the modifier include?,? - unsaturated carboxylic acids, polyhydric alcohols, and phenols. Of these,?,? - unsaturated carboxylic acids are preferred. These modifiers may be used singly or in combination of two or more. When, for example, not only?,? - unsaturated carboxylic acids but also polyhydric alcohols and phenols are used in combination, they may be reacted simultaneously or sequentially.

The?,? - unsaturated carboxylic acids are not particularly limited and include, for example, acrylic acid, methacrylic acid, fumaric acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, citraconic acid, And the like.

Examples of the polyhydric alcohols include, but are not particularly limited to, dihydric alcohols such as ethylene glycol, propylene glycol, neopentadiol, tetramethylene glycol and 1,3-butanediol; trihydric alcohols such as glycerin and pentaerythritol; And amino alcohols such as triethanolamine and tripropanolamine.

The styrenic resin is not particularly limited and includes, for example, polystyrene, styrene-maleic acid copolymer, styrene-maleic anhydride copolymer, styrene-maleimide copolymer, styrene-butadiene copolymer, styrene- Styrene-butadiene-methacrylate copolymer, and modified products thereof. In the case of a copolymer containing a monomer other than styrene, the content of styrene is preferably 50% by mass or more.

Examples of the olefin resin include, but are not limited to, polyethylene, an ethylene-maleic acid copolymer, an ethylene-maleic anhydride copolymer, an ethylene-maleimide copolymer, an ethylene-acrylate copolymer, Maleic acid-modified polyethylene, maleic anhydride-modified polyethylene, polypropylene, maleic acid-modified polypropylene, and maleic anhydride-modified polypropylene. Further, in the case of a copolymer containing a monomer other than olefin, it is preferable that the total content of the olefin is 50 mass% or more.

The acrylic acid resin is not particularly limited, and examples thereof include acrylic acid homopolymer, acrylic acid-acrylic acid ester copolymer, acrylic acid-butyl copolymer, acrylic acid-maleic acid copolymer, and modified products thereof. In the case of a copolymer containing a monomer other than acrylic acid, it is preferable that the total content of acrylic acid is 50 mass% or more.

An example of an analysis method in the case where the carbon nanofiber aggregate of the present embodiment includes a resin as the component (B) will be described. First, the resin component contained in the carbon nanofiber aggregate is identified by IR measurement. Then, a solvent capable of dissolving the resin is selected and dissolved in a solvent to obtain a solution. The component (B) can be identified by separating the solution into a soluble component and an insoluble component, and analyzing the insoluble component by IR, NMR, pyrolysis and mass spectrometry.

From the viewpoint of the aggregation of the carbon nanofibers (A) and the dispersibility of the carbon nanofiber aggregates in the thermoplastic resin, the total content of the component (B) relative to 100 parts by mass of the component (A) is preferably 0.1 to 50 mass More preferably from 0.1 to 40 parts by mass, and still more preferably from 0.5 to 30 parts by mass.

The component (B) is preferably emulsified. (B) is emulsified, it is presumed that the above-described tertiary aggregates can be connected more firmly. The method of emulsifying the component (B) is not particularly limited, but a method of emulsifying the component (B) using a surfactant (C) is preferred. From this point of view, the carbon nanofiber agglomerates of the present embodiment are obtained by mixing at least one selected from the group consisting of (A) carbon nanofibers, (B) modified rosin, styrene resin, olefin resin and acrylic acid resin, (C) a surfactant.

Examples of the emulsification method include, but are not limited to, a solvent emulsification method, a solventless emulsification method, and a phase-inversion emulsification method. The carbon nanofiber agglomerates of the present embodiment are preferably produced by mixing (wet mixing, etc.) the components (A) and (B) emulsions. As to the emulsion of the component (B), it is more preferable that the component (B) is emulsified by the component (C).

The component (C) is not particularly limited, and examples thereof include anionic surfactants, nonionic emulsifiers, amphoteric emulsifiers, and synthetic high molecular weight emulsifiers.

Examples of the anionic surfactant include, but are not limited to, fatty acids such as sodium stearate, sodium oleate and sodium lauryl sulfate, sodium dodecylbenzenesulfonate and sodium dodecyldiphenylether disulfonate.

Examples of the nonionic surfactant include, but are not limited to, polyoxyethylene alkyl (or alkenyl) ethers, polyethylene alkyl phenyl ethers, sorbitan higher fatty acid esters, polyoxyethylene higher fatty acid esters, glycerin Higher fatty acid esters, polyoxyethylene-polyoxypropylene block polymers, and the like.

Examples of the amphoteric surfactant include, but are not limited to, aminocarboxylic acid, imidazoline betaine, carboxybetaine, sulphobetaine, (ethylene oxide or propylene oxide) and (alkylamine or diamine) And sulfated and sulfonated adducts of the resulting condensates.

Examples of the synthetic high molecular weight surfactant include, but are not limited to, polymerizable monomers (e.g., styrene, acrylic acid, acrylic acid ester,? -Methylstyrene, vinyltoluene, maleic acid, acrylamide, (Such as sodium hydroxide, potassium hydroxide, ammonia, or the like) obtained by polymerizing two or more kinds of sulfonic acid, sulfonic acid, isoprene sulfonic acid, vinyl sulfonic acid, allyl sulfonic acid, 2- (meth) acrylamide- Or the like), and dispersing or solubilizing in water, and the like.

From the viewpoint of emulsifying the component (B), the carbon nanofiber aggregate of the present embodiment is obtained by mixing 100 parts by mass of the component (A), 0.1 to 50 parts by mass of the component (B), 0.01 to 30 mass (A) component, 0.1 to 40 parts by mass of the component (B), and 0.01 to 20 parts by mass of the component (C). When the content of the components (A) to (C) is in the above range, carbon nanofiber aggregates can be obtained by efficiently connecting the particles composed of the carbon nanofibers (B) and the component (C). In addition, when the thermoplastic resin and the carbon nanofiber aggregate are melted and kneaded, the molten resin may penetrate further into the voids of the carbon nanofiber aggregate. In addition, shearing force generated at the time of melt kneading is also applied, and the carbon nanofibers can be dispersed in the thermoplastic resin in a state in which the carbon nanofibers are unwound. As a result, the carbon nanofibers can be highly charged with good dispersibility in the thermoplastic resin. Further, it is also possible to prevent the fiber length of the carbon nanofiber as a raw material from being damaged during melt-kneading.

The average particle diameter of the emulsion of the component (B) is preferably 0.05 to 5 占 퐉, more preferably 0.1 to 1 占 퐉. In order to obtain such an average particle diameter, the conditions such as the type and amount of the surfactant used for preparing the emulsion, the agitating force of the solution, and the like may be appropriately adjusted. The average particle diameter referred to herein refers to the volume average particle diameter. The volume average particle diameter can be measured using a laser diffraction / scattering method particle size distribution meter. The emulsion particle of component (B) is preferably spherical.

Further, in the present embodiment, the value of P1 in the equation (1) can be further controlled by adjusting the average particle diameter of the emulsion, for example. For example, by using an emulsion having a small average particle diameter, the value of P1 tends to be large, and by using an emulsion having a large average particle diameter, the value of P1 tends to be small. When the average particle diameter of the emulsion of the component (B) is 5 m or less, the value of P1 tends to become large, and particles of the emulsion of the component (B) are arranged only in the pores of the third agglomerates of the carbon nanofibers . It is also possible to suppress the inclusion of the emulsion particles of the component (B) into the pores formed by the secondary aggregates corresponding to the accumulated pore volume Q2, the pores formed between the primary aggregates, and the pores of the primary aggregate. As a result, it is possible to realize more preferable spatial arrangement of the carbon nanofibers. Accordingly, when the carbon nanofiber aggregate of the present embodiment is melt-kneaded with the thermoplastic resin, the dispersibility of the carbon nanofiber aggregate to the thermoplastic resin can be further improved (however, the operation of the present embodiment is not limited to these ).

The value of P1 / P2 in the formula (2) can be further controlled by adjusting the average particle diameter of the emulsion, the average fiber diameter of the carbon nanofiber, and the blending amount of the component (B). For example, when an emulsion having a small average particle diameter is used, the value of P1 / P2 tends to be large, and the use of an emulsion having a large average particle diameter tends to decrease the value of P1 / P2 have. By setting the content of the component (B) to 100 parts by mass of the carbon nanofibers to 50 parts by mass or less, voids formed between the secondary aggregates corresponding to the accumulated pore volume Q2, pores formed between the primary aggregates, and It is possible to inhibit the emulsion particles of the component (B) from entering the pores of the primary aggregate. As a result, it is possible to realize more preferable spatial arrangement of the carbon nanofibers. Accordingly, when the carbon nanofiber aggregate of the present embodiment is melt-kneaded with the thermoplastic resin, the dispersibility of the carbon nanofiber aggregate to the thermoplastic resin can be further improved (however, the operation of the present embodiment is not limited to these ).

The value of Q2 / (Q1 + Q2) in the formula (3) can be further controlled by adjusting the average particle diameter of the emulsion and the amount of the component (B). For example, by using an emulsion having a small average particle diameter, it is possible to increase the value of Q2 / (Q1 + Q2), and by using an emulsion having a large average particle diameter, the value of Q2 / (Q1 + Q2) There is a tendency to be able to. When the content of the component (B) relative to 100 parts by mass of the carbon nanofibers is 50 parts by mass or less, voids formed between the secondary aggregates corresponding to the accumulated pore volume Q2, voids formed between the primary aggregates and 1 It is possible to inhibit the component (B) from entering the pores of the tea aggregate. Therefore, the value of Q1 becomes smaller, and the value of Q2 tends to be maintained at the value of Q2 of the raw-material carbon nanofibers. When the average particle diameter of the emulsion is 0.05 mu m or more, the value of Q1 tends to decrease. Accordingly, when the carbon nanofiber aggregate of the present embodiment is melt-kneaded with the thermoplastic resin, the dispersibility of the carbon nanofiber aggregate to the thermoplastic resin can be further improved (however, the operation of the present embodiment is not limited to these ).

The carbon nanofiber agglomerates of the present embodiment are preferably produced by, for example, a wet mixing method of the emulsion comprising the component (A), the component (B), and the component (C). Examples of the method for producing the carbon nanofiber aggregate containing the component (A), the component (B) and the component (C) include the following methods. The raw materials such as the component (A), the component (B) and the component (C) are mixed with a high-speed stirrer such as a Henschel mixer or a super mixer such as a ball mill, a paint shaker, a roller type kneader, a single screw extruder, A blender such as a multi-screw extruder, a mixer, a media mill or the like. The obtained mixture is assembled and formed into an extruder, a compression molding machine, a stirrer, a fluidized bed granulator or the like, and dried with a drier or a heater to produce a carbon nanofiber aggregate. In particular, it is preferable to use a mixer capable of obtaining a high shearing force, such as a high-speed stirrer such as a Henschel mixer, a super mixer, and a multi-screw extruder such as a twin screw extruder.

The carbon nanofiber agglomerates of the present embodiment preferably have a content of carbon nanofiber agglomerates having a particle size passing through a sieve having a nominal scale size of more than 0.3 mm and not more than 4.75 mm specified in JIS Z8801-1 of 90% More preferably at least% by mass. Specifically, by classifying the carbon nanofiber agglomerates by the above-mentioned sieve, the dispersibility to a thermoplastic resin described later is further improved. In view of this, in particular, the content of the carbon nanofiber aggregates having the particle size passing through the sieve having the nominal scale size of more than 0.3 mm and not more than 4.75 mm, which includes the component (A) and the component (B) and which is defined in JIS Z8801-1 More preferably 90 mass% or more.

&Lt; Thermoplastic resin composition &

The carbon nanofiber agglomerates described above may be all combined with a thermoplastic resin to form a thermoplastic resin composition. Particularly, the carbon nanofiber agglomerates of this embodiment can exhibit excellent dispersibility that can not be achieved by the conventional composite material of carbon nanofibers and thermoplastic resin. As a result, excellent performance can be exhibited even as a thermoplastic resin composition. All of these thermoplastic resin compositions are excellent in physical properties such as mechanical properties, electrical properties, heat transfer properties and the like. Hereinafter, the thermoplastic resin composition of the present embodiment will be described.

The content of the carbon nanofiber aggregates in the thermoplastic resin composition of the present embodiment is not particularly limited, but the content of the carbon nanofiber aggregates relative to 100 parts by mass of the thermoplastic resin is preferably 0.01 to 80 parts by mass, Is 0.5 to 70 parts by mass, and more preferably 1 to 40 parts by mass. By setting the content of the aggregate of carbon nanofibers within the above range, it is possible to further improve the elastic modulus as the mechanical property, the electrical conductivity, the thermal conductivity, and the like without greatly impairing moldability and toughness.

The lower limit of the content of the carbon nanofiber aggregates is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, still more preferably 0.5 parts by mass or more, still more preferably 1 part by mass or more to be. When the lower limit of the content of the carbon nanofiber aggregates is within the above range, the conductivity can be easily imparted while maintaining the moldability and mechanical properties of the thermoplastic resin of the matrix.

Examples of the thermoplastic resin include, but not limited to, styrene resins, olefin resins, polyester resins, polycarbonate resins, acrylic acid resins, polyamide resins, ABS resins, modified PPE resins, , A thermoplastic polyimide resin, an aromatic polyether ketone, and a rubber-based resin. Of these, polyamide-based resins and polyolefin-based resins are preferable from the standpoints of economy and versatility. When a styrene resin, an olefin resin or an acrylic acid resin is used as the component (B), it is clear that these components are components of the above-described carbon nanofiber aggregate and can be distinguished from the above-mentioned thermoplastic resin.

Specific examples of the styrene-based resin include polystyrene and the like. Specific examples of the olefin resin include polyethylene, polypropylene, ethylene-propylene copolymer, and ethylene-vinyl acetate copolymer. Specific examples of the polyester-based resin include polyethylene terephthalate, polymethylene terephthalate, and polybutylene terephthalate. Specific examples of the polycarbonate resin include polycarbonate, polycarbonate-ABS alloy resin and the like. Specific examples of the acrylic acid-based resin include polymethyl methacrylate, acrylic acid-acrylic acid ester copolymer and the like. Specific examples of the polyamide-series resin include polyamide (PA) 6, PA11, PA12, PA66, PA610, PA6T, PA6I and PA9T. Specific examples of the modified PPE resin include PPE and polymer alloys such as any one selected from the group consisting of polystyrene, polyamide and polypropylene. Specific examples of the fluorine resin include polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinylidene fluoride, perfluoroalkoxy fluorine resin, tetrafluoroethylene-hexafluoropropylene copolymer, ethylene-tetrafluoroethylene copolymer And the like. Specific examples of the rubber-based resin include a styrene thermoplastic elastomer, a polyolefin thermoplastic elastomer, a polyamide thermoplastic elastomer, a polyester thermoplastic elastomer, and a thermoplastic polyurethane elastomer.

The thermoplastic resin composition of the present embodiment may further contain other components other than carbon nanofiber aggregates or thermoplastic resins.

In the thermoplastic resin composition of the present embodiment, the L / D ratio of the contained carbon nanofibers can be 50 or more. The L / D ratio is the ratio (L / D) of the average fiber length (L) of the carbon nanofibers to the average fiber diameter (D) of the carbon nanofibers. Also, the average fiber length as used herein refers to the weight average length. These average fiber diameters and average fiber lengths can be obtained by the following methods. First, the resin composition to be measured is put into a solvent, and a dispersion solution of the dispersion solution or the pyrolyzed residue of only the resin is prepared. The dispersion solution is filtered and dried to obtain a measurement sample. This measurement sample can be obtained by observation with a scanning electron microscope or a transmission electron microscope and statistical analysis of the observed image.

Conventionally, there is a problem that when the carbon nanofibers are kneaded with the thermoplastic resin, the carbon nanofibers are easily broken or broken because the dispersion state of the carbon nanofibers is not sufficiently controlled. Therefore, there is a tendency that a problem that it is difficult to maintain a high L / D ratio tends to occur. However, in the present embodiment, there is no such a problem by using a carbon nanofiber aggregate having excellent dispersibility in a thermoplastic resin.

As the carbon nanofiber agglomerates in the thermoplastic resin composition, 10 pellets molded from a thermoplastic resin composition were cut one by one with a microtome and observed with an optical microscope (400 times) at a viewing angle of 200 占 퐉 占 200 占 퐉, It is preferable that the major axes of the carbon nanofiber aggregates observed in the observation region of the optical microscope are all less than 10 mu m. Since such a dispersion state can be taken in the thermoplastic resin composition, various physical properties including electrical properties can be improved as a composite material of a thermoplastic resin and a carbon nanofiber aggregate.

The method for producing the thermoplastic resin composition of the present embodiment preferably has a step of melting and kneading the carbon nanofiber aggregate and the thermoplastic resin to obtain the thermoplastic resin composition. As a specific example, the carbon nanofiber agglomerate and the thermoplastic resin are mixed by hand mixing in a mixer or a bag, and then kneaded by a batch type kneader such as a Banbury type mixer, a roll type kneader, a single screw extruder, And a method of heating and melt kneading with a multi-screw extruder such as an axial extruder. In the conventional composite material of the carbon nanofibers and the thermoplastic resin, it is difficult to form a good dispersion state of the carbon nanofibers in the thermoplastic resin. By using the carbon nanofiber agglomerates of the present embodiment, the thermoplastic resin By merely kneading with the resin, the above-described excellent dispersion state can be constituted. As a method for producing the thermoplastic resin composition of the present embodiment, it is preferable to heat-melt knead the mixture using a batch-type kneader such as a kneader or a multi-screw extruder such as a twin screw extruder.

In the carbon nanofiber agglomerate obtained by the above method, the particles of the above-mentioned emulsion preferentially enter into the gap between the tertiary agglomerate structures, not the primary aggregation structure of the aggregated carbon nanofibers or the secondary aggregation structure . Therefore, when the melted thermoplastic resin and the carbon nanofiber aggregate are mixed, the thermoplastic resin can easily penetrate into the voids of the carbon nanofiber aggregate. As a result, the carbon nanofiber agglomerates can be highly charged. Further, it is presumed that the aggregation of carbon nanofibers can be dispersed in the thermoplastic resin composition by applying the shearing force at the time of melt kneading (however, the action of this embodiment is not limited to these).

Example

Hereinafter, the present invention will be described in detail with reference to examples and comparative examples, but the present invention is not limited to these examples at all. In the present embodiment, the following raw materials were used.

[Component (A)] [

1) Multilayer carbon nanofibers having an average fiber diameter of 150 nm (trade name &quot; VGCF &quot;, manufactured by Showa Denko K.K.)

2) Multilayer carbon nanofibers having an average fiber diameter of 80 nm (trade name "VGCF-S" manufactured by Showa Denko K.K.)

3) Multilayer carbon nanofibers having an average fiber diameter of 15 nm (trade name "VGCF-X" manufactured by Showa Denko K.K.)

[Component (B)] [

1) modified rosin (trade name &quot; 135GN &quot;, manufactured by Harima Kagaku Co., Ltd.)

2) Styrene-ethylene butylene-styrene copolymer (trade name: "TUPTEC H1041", manufactured by SEBS Asahi Chemical Industry Co., Ltd.)

3) Amine-modified styrene-ethylene butylene-styrene copolymer (modified SEBS; trade name: TUPTEC MP-10, manufactured by Asahi Chemical Industry Co., Ltd.)

4) Polystyrene (trade name &quot; H77 &quot;, manufactured by PS Japan)

5) Styrene-maleic anhydride copolymer (Sartomer Japan, trade name: "SMA3000", manufactured by CRAY VALLEY)

6) Esterified styrene-maleic anhydride copolymer (Sartomer Japan, trade name "SMA3840", manufactured by CRAY VALLEY)

7) Ethylene-vinyl acetate copolymer (trade name &quot; EV150 &quot;, manufactured by Mitsui DuPont)

8) Polyacrylic polymer (Solvent-type pressure-sensitive adhesive polymer, trade name: AARON TAKK S-1601,

9) Synthetic styrene-butadiene type aqueous emulsion (synthetic SBR type emulsion; described later)

10) Synthetic acrylic water-based emulsion (synthetic polyacrylic emulsion, described later)

[Component (C)] [

Surfactants:

1) "Newcol 2320-SN" (manufactured by Nippon Yakuhin Kogyo Co., Ltd .: 24% active ingredient)

2) 50% aqueous sodium dodecylbenzenesulfonate reagent (manufactured by Junsei Chemical Co., Ltd.)

[Thermoplastic resin]

1) Polyamide (PA: Leona 1300S, manufactured by Asahi Chemical Industry Co., Ltd.)

2) Low density polyethylene (PE: Suntech LD F1920, trade name, manufactured by Asahi Chemical Industry Co., Ltd.)

3) Polypropylene (PP; manufactured by Prime Polymer Co., Ltd., trade name: J707G)

[Carbon nanofiber-containing resin composition (Production of pellets)]

The blend ratio of the carbon nanofibers to the thermoplastic resin was adjusted to 5% by mass to prepare pellets. As the thermoplastic resin, polyamide, polyethylene or polypropylene was used. Strands were obtained under the following conditions, and this was cut into pellets.

· Used kneading machine: small kneader for laboratory ("Xplore" manufactured by DSM Corporation)

When a polyamide resin composition was prepared by kneading polyamide and carbon nanofibers: kneading temperature 300 占 폚, kneading time 2 minutes, revolution number 100 rpm

When polyethylene and carbon nanofibers were kneaded to make a polyethylene resin composition: kneading temperature 180 占 폚, kneading time 2 minutes, revolution number 100 rpm

When polypropylene and carbon nanofibers were kneaded to make a polypropylene resin composition: kneading temperature 250 占 폚, kneading time 2 minutes, rotation number 100 rpm

[Carbon nanofiber-containing resin composition (Production of molded article for evaluation of physical properties)]

A dumbbell compact of Type 3 conforming to ISO 37 was prepared and used as a molding for evaluation of physical properties. Specifically, a dumbbell molded article was produced in accordance with the following method.

First, a small injection molding machine jacket ("Xplore" manufactured by DSM Corporation) was connected to the strand outlet of the small kneader for a reactor. Then, the molten resin composition (polyamide resin composition, polyethylene resin composition, polypropylene resin composition) was injected into the jacket of a small injection molding machine. When the polyamide resin composition was injected into the jacket of a small injection molding machine, the jacket temperature was set at 300 캜. When the polyethylene resin composition was injected into the small injection molding machine jacket, the jacket temperature was set at 200 占 폚. When the polypropylene resin composition was injected into the small injection molding machine jacket, the jacket temperature was set at 250 占 폚.

Next, the small injection molding machine jacket was removed from the small kneader for laboratory use, and this small injection molding machine jacket was set in a dumbbell mold of Type 3 conforming to ISO 37. Then, the resin composition inside the small injection molding machine jacket was extruded into the mold by using a pressure cylinder connected to the rear portion of the small injection molding machine jacket. The injection conditions were as follows. The thus obtained dumbbell formed article was used as a molded article for evaluation of physical properties.

· Injection pressure 11 bar, injection time 30 seconds

Mold temperature of polyamide resin composition: 80 DEG C

Mold temperature of the polyethylene resin composition: 40 DEG C

Mold temperature of the polypropylene resin composition: 40 DEG C

[Measurement of pore volume, etc. (P1, P2, Q1, Q2)]

The pore volume of the aggregate of carbon nanofibers was measured using a mercury porosimeter ("PoreMaster PM-33GT", manufactured by Quantachrom). A cell having a volume of 3 ml was filled with the measurement sample and subjected to degassing as a pretreatment, and then the measurement was carried out.

The measured data points were measured at 70 or more in the range of pore diameter 3 ~ 100,000 ㎚. The obtained data was interpreted as "Quantachrome Poremaster for Windows (trademark) version 3.0" manufactured by Quantachrome.

P1 is the maximum peak value in the range of pore diameters of from 2,500 nm to 100,000 nm. P2 is the maximum peak value in the region where the pore diameter is 6 nm or more and less than 2,500 nm. Q1 is the total pore volume in the range of pore diameters of from 2,500 nm to 100,000 nm, and shows the pore volume in this range. Q2 is the total pore volume in the range of the pore diameter of 6 nm or more and less than 2,500 nm, and shows the pore volume in this range.

[Evaluation of non-acidity of aggregates of carbon nanofibers]

5 g of carbon nanofiber agglomerates were put in a bag made of polyethylene (1 L), sealed, and then vibrated left and right at a speed of 50 times for 20 seconds at an amplitude of 50 cm. The suspended state of the aggregated carbon nanofibers after the vibration was visually observed. The non-acidity was evaluated based on the following criteria.

G: Float of aggregate sinks within 30 seconds

B: Floating aggregate for more than 30 seconds

[Evaluation of dispersibility of aggregates of carbon nanofibers]

10 pieces of arbitrary pellets of the thermoplastic resin composition containing 5 mass% of the carbon nanofiber aggregate obtained in the above were cut one by one into microtomes and used as observation samples. The observation sample was observed under an optical microscope (200 占 퐉 占 200 占 퐉, magnification: 400x), and the dispersibility was evaluated based on the following criteria.

A: Only carbon nanofiber agglomerates having a major axis length of less than 10 mu m were observed in the observation region of the optical microscope. (All of the long axes of aggregated carbon nanofibers observed in the observation region of the optical microscope were all less than 10 mu m).

B: In the observation region of the optical microscope, the number of carbon nanofiber aggregates having a major axis length of 10 mu m or more and less than 30 mu m was 10 or less.

C: In the observation region of the optical microscope, the number of carbon nanofiber agglomerates having a major axis length of 30 탆 or more and less than 50 탆 was 5 or less.

D: At least one aggregate of carbon nanofibers having a major axis length of 50 m or more was observed in the observation region of the optical microscope.

[Measurement of maximum filling rate for polyamide resin]

The maximum filling rate of the carbon nanofiber aggregate to the polyamide resin was determined in accordance with the following method.

First, the total amount of the polyamide resin composition was set to 3 kg. Next, the content of the carbon nanofiber agglomerates in the polyamide resin composition was gradually increased, and the resulting polyamide resin composition was subjected to extrusion molding by a twin-screw extruder ("KZW15" manufactured by Techno Bell, screw diameter 15 mm, L / D ratio 45) The maximum charged amount of the aggregated carbon nanofibers until the continuous strands could not be obtained when kneading extrusion (temperature 300 ° C, rotation number 250 rpm) was obtained. Based on the following formula, the maximum filling rate was obtained from the maximum filling amount.

Maximum charging rate (mass%) = (maximum charged amount (kg) of carbon nanofiber aggregate) / (total amount (3 kg) of polyamide resin composition) x 100

[Evaluation of Conductivity]

A polyamide resin composition pellet containing carbon nanofiber aggregates in an amount of 2.5 mass% was prepared, and a flat metal mold (130 mm x 130 mm x 3 mm) set at 80 占 폚 using an IS150E molding machine manufactured by Toshiba Machinery Co., , A screw rotation speed of 200 rpm, a resin temperature of 290 DEG C, and a primary pressure time of 1.2 seconds to obtain a test piece. The surface resistance value of the obtained test piece was measured, and the conductivity was evaluated. A copper plate having an aspect ratio of 1 cm was placed on the test piece at intervals of 1 cm and the lead from the copper plate was connected to a resistance meter ("R8340A type", manufactured by Advantest Co., Ltd.) Respectively. In the measurement, three specimens were each prepared, and five specimens were measured at each of the specimens, and the average of the measured values of 15 points in total was calculated.

[Evaluation of tensile breaking strength and tensile elongation at break]

The tensile breaking strength and tensile elongation at break were measured at a tensile rate of 50 mm / min under constant temperature and humidity conditions of 23 ° C and a humidity of 50% in accordance with JIS K7161 (Plastics-Tensile Properties Test Method).

[L / D ratio measurement of carbon nanofibers]

The L / D ratio of the carbon nanofibers contained in the resin composition was measured by the following method. First, 0.1 g of the resin composition is put into 50 ml of a solvent, and the mixture is stopped to dissolve the resin component. As the solvent, for example, hexafluoroisopropanol (HFIP) was used for polyamide 66 or polyethylene terephthalate, toluene was used for styrene resin, and ethyl acetate was used for polycarbonate.

In the case where the olefin resin such as polyethylene or polypropylene is hardly dissolved in a solvent, the following treatment is carried out. The resin composition was pyrolyzed at 350 DEG C using an electric furnace under a nitrogen gas atmosphere to obtain a residue. 0.1 g of the obtained residue was added to 50 ml of xylene to obtain a solution.

The obtained solution was stirred with an ultrasonic bath for 20 minutes, the solution was dropped onto a 0.025 mu m cellulose filter, and naturally dried to obtain a measurement sample. The obtained measurement sample was observed using a scanning electron microscope ("S-4700" manufactured by Hitachi High Technologies, Ltd.) or a transmission electron microscope ("H-600" manufactured by Hitachi High Technologies). The captured image was statistically analyzed using "Image-pro plus" (number of measurements 200). Then, the ratio of the weight average length (L) to the diameter (D) of the carbon nanofiber was determined as an L / D ratio.

[Example 1]

100 g of the modified rosin was dissolved in 300 g of toluene, and a toluene solution of the modified rosin was prepared. Separately, 900 ml of an aqueous solution having an active ingredient concentration of 10% by mass in a surfactant (trade name: Newcol 2320-SN) was separately prepared. Then, these were added to the toluene solution and mixed by stirring to emulsify. This was again used as a fine emulsion by using a high-pressure emulsifier (manufactured by Mann-Gauling Co.). The obtained fine emulsion was distilled under reduced pressure under a condition of 100 mmHg to remove toluene to obtain an organic emulsion having a volume average particle diameter of 0.3 mu m. The volume average particle diameter was measured in accordance with the laser diffraction scattering method. Specifically, D50 of the particle size distribution was obtained using "SALD-300V" manufactured by Shimadzu Corporation.

Next, 100 g of carbon nanofiber (trade name &quot; VGCF &quot;) and water were added to a Henschel mixer having a capacity of 20 L to prepare a capacity of about half the Henschel mixer capacity.

The organic emulsion prepared above was added to an organic emulsion at a ratio such that the ratio of the solid content in the organic emulsion to the 100 mass part of the carbon nanofiber (trade name &quot; VGCF &quot;) was 10 mass parts, Followed by stirring and mixing.

The resultant mixture was in the form of a slurry, which was put into a wet extrusion granulator manufactured by Dalton Corporation to obtain a columnar granulated product. The obtained granulation product was dried in an air blow dryer of Yamato Scientific Co., Ltd. under the conditions of 90 ° C for 2 hours to obtain a carbon nanofiber agglomerate. The obtained carbon nanofiber agglomerates were classified using a sieve having a nominal graduation size of 2.36 mm specified in JIS Z8801-1. Carbon nano aggregates passing through this sieve were further classified using a sieve having a nominal scale size of 1.18 mm. Then, the carbon nano aggregates remaining in the sieve were vacuum-dried at 80 ° C to obtain a desired aggregate of carbon nanofibers.

The obtained carbon nanofiber agglomerates were used as resin compositions in the following manner, and their physical properties were evaluated.

First, a polyamide resin composition containing 95 mass% of polyamide and 5 mass% of carbon nanofiber aggregate was produced in accordance with the above-described method. Similarly, a polyethylene resin composition containing 95 mass% of polyethylene and 5 mass% of carbon nanofiber aggregates was prepared. These resin compositions were used for evaluation of dispersibility.

Next, a polyamide resin composition containing 97.5% by mass of polyamide and 2.5% by mass of carbon nanofiber aggregate was produced in accordance with the above-described method. This resin composition was used for conductivity evaluation.

[Example 2]

Carbon nanofiber agglomerates were obtained in the same manner as in Example 1 except that "VGCF-S" was used instead of "VGCF" as the carbon nanofiber.

The obtained carbon nanofiber agglomerates were used as resin compositions in the following manner, and their physical properties were evaluated.

First, a polyamide resin composition containing 95 mass% of polyamide and 5 mass% of carbon nanofiber aggregate was produced in accordance with the above-described method. Similarly, a polyethylene resin composition containing 95 mass% of polyethylene and 5 mass% of carbon nanofiber aggregates was prepared. These resin compositions were used for evaluation of dispersibility.

Next, a polyamide resin composition containing 97.5% by mass of polyamide and 2.5% by mass of carbon nanofiber aggregate was produced in accordance with the above-described method. This resin composition was used for conductivity evaluation.

[Example 3]

Except that "VGCF-S" was used instead of "VGCF" as the carbon nanofiber, "SEBS" was used instead of the modified rosin, and "organic emulsion having a volume average particle diameter of 0.5 μm" was used as the carbon nanofiber Carbon nanofiber agglomerates were obtained.

The obtained carbon nanofiber agglomerates were used as resin compositions in the following manner, and their physical properties were evaluated.

First, a polyamide resin composition containing 95 mass% of polyamide and 5 mass% of carbon nanofiber aggregate was produced in accordance with the above-described method. Similarly, a polyethylene resin composition containing 95 mass% of polyethylene and 5 mass% of carbon nanofiber aggregates was prepared. These resin compositions were used for evaluation of dispersibility.

Next, a polyamide resin composition containing 97.5% by mass of polyamide and 2.5% by mass of carbon nanofiber aggregate was produced in accordance with the above-described method. This resin composition was used for conductivity evaluation.

[Example 4]

Carbon nanofiber agglomerates were obtained in the same manner as in Example 1 except that "VGCF-X" was used instead of "VGCF" as the carbon nanofiber.

The obtained carbon nanofiber agglomerates were used as resin compositions in the following manner, and their physical properties were evaluated.

First, a polyamide resin composition containing 95 mass% of polyamide and 5 mass% of carbon nanofiber aggregate was produced in accordance with the above-described method. Similarly, a polypropylene resin composition containing 95 mass% of polypropylene and 5 mass% of carbon nanofiber aggregate was prepared. These resin compositions were used for evaluation of dispersibility.

Next, a polyamide resin composition containing 97.5% by mass of polyamide and 2.5% by mass of carbon nanofiber aggregate was produced in accordance with the above-described method. This resin composition was used for conductivity evaluation.

[Example 5]

Except that "VGCF-X" was used instead of "VGCF" as carbon nanofiber, modified SEBS was used instead of modified rosin, and organic emulsion having a volume average particle diameter of 0.5 μm was used. To obtain aggregates of carbon nanofibers.

The obtained carbon nanofiber agglomerates were used as resin compositions in the following manner, and their physical properties were evaluated.

First, a polyamide resin composition containing 95 mass% of polyamide and 5 mass% of carbon nanofiber aggregate was produced in accordance with the above-described method. Similarly, a polyethylene resin composition containing 95 mass% of polyethylene and 5 mass% of carbon nanofiber aggregates was prepared. These resin compositions were used for evaluation of dispersibility.

Next, a polyamide resin composition containing 97.5% by mass of polyamide and 2.5% by mass of carbon nanofiber aggregate was produced in accordance with the above-described method. This resin composition was used for conductivity evaluation.

[Example 6]

Except that "VGCF-X" was used instead of "VGCF" as the carbon nanofiber, PS was used instead of the modified rosin, and an organic emulsion having a volume average particle diameter of 0.5 μm was used, Carbon nanofiber agglomerates were obtained.

The obtained carbon nanofiber agglomerates were used as resin compositions in the following manner, and their physical properties were evaluated.

First, a polyamide resin composition containing 95 mass% of polyamide and 5 mass% of carbon nanofiber aggregate was produced in accordance with the above-described method. Similarly, a polyethylene resin composition containing 95 mass% of polyethylene and 5 mass% of carbon nanofiber aggregates was prepared. These resin compositions were used for evaluation of dispersibility.

Next, a polyamide resin composition containing 97.5% by mass of polyamide and 2.5% by mass of carbon nanofiber aggregate was produced in accordance with the above-described method. This resin composition was used for conductivity evaluation.

[Example 7]

Except that "VGCF-X" was used instead of "VGCF" as the carbon nanofiber and "organic emulsion (modified rosin)" was added so that the proportion of the organic emulsion to the solid matter in the organic emulsion with respect to 100 parts by mass of the carbon nanofiber was 5 parts by mass The carbon nanofiber agglomerates were obtained in the same manner as in Example 1. 3 shows a graph of mercury porosimetry results of the raw material carbon nanofibers and carbon nanofiber agglomerates in Example 7 as an example.

The obtained carbon nanofiber agglomerates were used as resin compositions in the following manner, and their physical properties were evaluated.

First, a polyamide resin composition containing 95 mass% of polyamide and 5 mass% of carbon nanofiber aggregate was produced in accordance with the above-described method. Similarly, a polypropylene resin composition containing 95 mass% of polypropylene and 5 mass% of carbon nanofiber aggregate was prepared. These resin compositions were used for evaluation of dispersibility.

Next, a polyamide resin composition containing 97.5% by mass of polyamide and 2.5% by mass of carbon nanofiber aggregate was produced in accordance with the above-described method. This resin composition was used for conductivity evaluation.

[Example 8]

, "VGCF-X" was used instead of "VGCF" as carbon nanofiber, modified SEBS was used instead of modified rosin, an organic emulsion having a volume average particle diameter of 0.6 μm was used, and 100 parts by mass of carbon nanofibers A carbon nanofiber agglomerate was obtained in the same manner as in Example 1 except that an organic emulsion (modified SEBS) was added so that the proportion of the organic emulsion in the solid matter was 5 parts by mass.

The obtained carbon nanofiber agglomerates were used as resin compositions in the following manner, and their physical properties were evaluated.

First, a polyamide resin composition containing 95 mass% of polyamide and 5 mass% of carbon nanofiber aggregate was produced in accordance with the above-described method. Similarly, a polypropylene resin composition containing 95 mass% of polypropylene and 5 mass% of carbon nanofiber aggregate was prepared. These resin compositions were used for evaluation of dispersibility.

Next, a polyamide resin composition containing 97.5% by mass of polyamide and 2.5% by mass of carbon nanofiber aggregate was produced in accordance with the above-described method. This resin composition was used for conductivity evaluation.

[Example 9]

Using VGCF-X instead of VGCF as the carbon nanofiber, using SEBS instead of the modified rosin, using an organic emulsion having an average volume particle diameter of 0.6 mu m, and using 100 parts by mass of the carbon nanofiber Carbon nanofiber agglomerates were obtained in the same manner as in Example 1 except that an organic emulsion (SEBS) was added so that the proportion of the organic emulsion in the solid matter was 5 mass parts.

The obtained carbon nanofiber agglomerates were used as resin compositions in the following manner, and their physical properties were evaluated.

First, a polyamide resin composition containing 95 mass% of polyamide and 5 mass% of carbon nanofiber aggregate was produced in accordance with the above-described method. Similarly, a polypropylene resin composition containing 95 mass% of polypropylene and 5 mass% of carbon nanofiber aggregate was prepared. These resin compositions were used for evaluation of dispersibility.

Next, a polyamide resin composition containing 97.5% by mass of polyamide and 2.5% by mass of carbon nanofiber aggregate was produced in accordance with the above-described method. This resin composition was used for conductivity evaluation.

[Example 10]

The use of "VGCF-X" instead of "VGCF" as the carbon nanofiber, the use of PS instead of the modified rosin, the use of an organic emulsion having an average volume particle diameter of 0.6 μm and the use of 100 parts of the carbon nanofiber Carbon nanofiber agglomerates were obtained in the same manner as in Example 1 except that an organic emulsion (PS) was added so that the proportion of the organic emulsion in the solid matter was 5 mass parts.

The obtained carbon nanofiber agglomerates were used as resin compositions in the following manner, and their physical properties were evaluated.

First, a polyamide resin composition containing 95 mass% of polyamide and 5 mass% of carbon nanofiber aggregate was produced in accordance with the above-described method. Similarly, a polypropylene resin composition containing 95 mass% of polypropylene and 5 mass% of carbon nanofiber aggregate was prepared. These resin compositions were used for evaluation of dispersibility.

Next, a polyamide resin composition containing 97.5% by mass of polyamide and 2.5% by mass of carbon nanofiber aggregate was produced in accordance with the above-described method. This resin composition was used for conductivity evaluation.

[Example 11]

Modified rosin and 100 g of styrene-maleic anhydride copolymer was dissolved in 300 g of propyl acetate to prepare a propyl acetate solution. Further, 900 ml of an aqueous solution containing 10% by mass of the active ingredient of sodium dodecylbenzenesulfonate was separately prepared, added to a propyl acetate solution, and mixed by stirring to emulsify. This was further converted into a fine emulsion by using a high-pressure emulsifier (produced by Mann-Gauling Co.). The fine emulsion was distilled under reduced pressure under a condition of 100 mmHg to remove the solvent to obtain an organic emulsion having a volume average particle diameter of 0.5 mu m. A carbon nanofiber agglomerate was obtained in the same manner as in Example 1 except that the organic emulsion was added to the organic emulsion so that the solid content in the organic emulsion was 5 parts by mass with respect to 100 parts by mass of the carbon nanofiber.

The obtained carbon nanofiber agglomerates were used as resin compositions in the following manner, and their physical properties were evaluated.

First, a polyamide resin composition containing 95 mass% of polyamide and 5 mass% of carbon nanofiber aggregate was produced in accordance with the above-described method. Similarly, a polypropylene resin composition containing 95 mass% of polypropylene and 5 mass% of carbon nanofiber aggregate was prepared. These resin compositions were used for evaluation of dispersibility.

Next, a polyamide resin composition containing 97.5% by mass of polyamide and 2.5% by mass of carbon nanofiber aggregate was produced in accordance with the above-described method. This resin composition was used for conductivity evaluation.

[Example 12]

100 g of an ethylene-vinyl acetate copolymer was used instead of the modified rosin. The ethylene-vinyl acetate copolymer was added to 300 g of toluene and dissolved by heating at 60 DEG C to prepare a toluene solution. 900 ml of an aqueous solution containing 10% by mass of the active ingredient of sodium dodecylbenzenesulfonate was separately prepared, added to a toluene solution and stirred to mix and emulsify. This was further converted into a fine emulsion by using a high-pressure emulsifier (produced by Mann-Gauling Co.). The fine emulsion was subjected to distillation under reduced pressure of 100 mmHg to remove toluene to obtain an organic emulsion having a volume average particle diameter of 0.4 탆. Carbon nanofiber agglomerates were obtained in the same manner as in Example 4 except that the organic emulsion was added to the organic emulsion so that the solid content in the organic emulsion was 5 parts by mass with respect to 100 parts by mass of the carbon nanofibers.

The obtained carbon nanofiber agglomerates were used as resin compositions in the following manner, and their physical properties were evaluated.

First, a polyamide resin composition containing 95 mass% of polyamide and 5 mass% of carbon nanofiber aggregate was produced in accordance with the above-described method. Similarly, a polyethylene resin composition containing 95 mass% of polyethylene and 5 mass% of carbon nanofiber aggregates was prepared. These resin compositions were used for evaluation of dispersibility.

Next, a polyamide resin composition containing 97.5% by mass of polyamide and 2.5% by mass of carbon nanofiber aggregate was produced in accordance with the above-described method. This resin composition was used for conductivity evaluation.

[Example 13]

100 g of an esterified styrene-maleic anhydride copolymer was used instead of the modified rosin. The esterified styrene-maleic anhydride copolymer was added to 300 g of toluene and heated at 60 DEG C to dissolve to prepare a toluene solution. 900 ml of an aqueous solution containing 10% by mass of the active ingredient of sodium dodecylbenzenesulfonate was separately prepared, added to a toluene solution and stirred to mix and emulsify. This was further converted into a fine emulsion by using a high-pressure emulsifier (produced by Mann-Gauling Co.). The fine emulsion was subjected to distillation under reduced pressure of 100 mmHg to remove toluene to obtain an organic emulsion having a volume average particle diameter of 0.4 탆. Carbon nanofiber agglomerates were obtained in the same manner as in Example 4 except that the organic emulsion was added to the organic emulsion so that the solid content in the organic emulsion was 5 parts by mass with respect to 100 parts by mass of the carbon nanofibers.

The obtained carbon nanofiber agglomerates were used as resin compositions in the following manner, and their physical properties were evaluated.

First, a polyamide resin composition containing 95 mass% of polyamide and 5 mass% of carbon nanofiber aggregate was produced in accordance with the above-described method. Similarly, a polyethylene resin composition containing 95 mass% of polyethylene and 5 mass% of carbon nanofiber aggregates was prepared. These resin compositions were used for evaluation of dispersibility.

Next, a polyamide resin composition containing 97.5% by mass of polyamide and 2.5% by mass of carbon nanofiber aggregate was produced in accordance with the above-described method. This resin composition was used for conductivity evaluation.

[Example 14]

A toluene solution having a polyacrylic polymer solid content concentration of 30% was prepared. Separately, 900 ml of an aqueous solution containing 10% by mass of the active ingredient of sodium dodecylbenzenesulfonate was prepared. These solutions were stirred and mixed to emulsify. This was further converted into a fine emulsion by using a high-pressure emulsifier (produced by Mann-Gauling Co.). The fine emulsion was subjected to distillation under reduced pressure of 100 mmHg to remove toluene to obtain an organic emulsion having a volume average particle diameter of 0.6 탆. Carbon nanofiber agglomerates were obtained in the same manner as in Example 4 except that the organic emulsion was added to the organic emulsion so that the solid content in the organic emulsion was 5 parts by mass with respect to 100 parts by mass of the carbon nanofibers.

The obtained carbon nanofiber agglomerates were used as resin compositions in the following manner, and their physical properties were evaluated. First, a polyamide resin composition containing 95 mass% of a polyamide and 5 mass% of a carbon nanofiber aggregate was prepared and evaluated for dispersibility in accordance with the above-described method. Next, a polyamide resin composition containing 97.5% by mass of polyamide and 2.5% by mass of carbon nanofiber aggregates was prepared and used for conductivity evaluation in accordance with the above-described method.

[Example 15]

The seed aqueous dispersion for emulsion polymerization was synthesized in accordance with the following method. The inside of the temperature-adjustable reactor equipped with a stirrer was previously purged with nitrogen, and then 170 parts by mass of ion-exchanged water (hereinafter, unless otherwise stated, based on the mass part, except for the ion-exchanged water, the unsaturated monomer, 10 parts by mass of sodium dodecylbenzenesulfonate, 0.1 part by mass of sodium hydroxide and 2.5 parts by mass of sodium persulfate were added to the mixture, and the mixture was stirred at 40 占 폚. Then, 45 parts by mass of styrene, 50 parts by mass of 2-ethylhexyl acrylate, 2 parts by mass of 2-hydroxyethyl acrylate, and 2 parts by mass of acrylic acid were added in a total amount, followed by addition of a reducing agent aqueous solution , 0.5 parts by mass of sodium hydrogen sulfite and 0.0005 parts by mass of ferric nitrate) was added in one portion. Since the temperature in the polymerization system immediately after the addition of the reducing agent aqueous solution was increased, the temperature was controlled at 90 占 폚. After maintaining the temperature at 90 캜 for 2 hours, the temperature in the polymerization system was lowered to obtain a seed dispersion for emulsion polymerization. The solid content concentration of the resultant seed dispersion for emulsion polymerization was 40%.

The inside of the reaction vessel equipped with the stirrer and the temperature control jacket was substituted with nitrogen. Then, 72 parts by mass of ion-exchanged water, 0.3 parts by mass (solid content) of an aqueous dispersion of seed particles having an average particle diameter of about 40 nm (styrene-ethylhexyl acrylate-acrylic acid copolymer; Tg = 11 DEG C), sodium lauryl sulfate 0.1 part by mass (solid content) was charged into a reaction vessel, and the internal temperature was raised to 80 캜 while stirring at a rotation speed of 280 rpm. Thereafter, a mixture containing 69 parts by mass of styrene (styrene deoxidized by vacuum degassing), 30 parts by mass of butadiene, 1 part by mass of acrylic acid, 0.4 parts by mass of tert-dodecylmercaptan, and 0.05 parts by mass of- Was added over 4 hours. Approximately 21 parts by mass of water, 0.1 part by mass (solid content) of sodium laurylsulfate, 0.1 part by mass (solid content) of sodium hydroxide and 0.7 part by mass (solid content) of peroxodisulfate was stirred for 14 hours Lt; / RTI &gt;

After completion of the polymerization, the temperature of the reaction product was maintained at 80 캜 for about 1 hour. Sodium hydroxide was then added to adjust the pH of the reaction to about 8.0. Subsequently, the residual monomer was removed by steam stripping, and then the reaction product was cooled and filtered through an 80-mesh filter column to obtain a latex. The solid content (130 캜, drying method) of the obtained latex was adjusted to 50% by weight to obtain an organic emulsion. The volume average particle diameter of the obtained organic emulsion was 0.3 mu m.

Further, except that "VGCF-X" was used instead of "VGCF" as the carbon nanofiber, and the organic emulsion was added so that the solid content in the organic emulsion was 5 parts by mass with respect to 100 parts by mass of the carbon nanofiber The carbon nanofiber agglomerates were obtained in the same manner as in Example 1.

The obtained carbon nanofiber agglomerates were used as resin compositions in the following manner, and their physical properties were evaluated. First, a polyamide resin composition containing 95 mass% of a polyamide and 5 mass% of a carbon nanofiber aggregate was prepared and evaluated for dispersibility in accordance with the above-described method. Next, a polyamide resin composition containing 97.5% by mass of polyamide and 2.5% by mass of carbon nanofiber aggregates was prepared and used for conductivity evaluation in accordance with the above-described method.

[Example 16]

A reaction vessel equipped with a stirrer, a reflux condenser, a dropping vessel, and a thermometer was charged with 8 parts by mass of methacrylic acid, 52 parts by mass of methyl methacrylate, 40 parts by mass of butyl acrylate, 300 parts by mass of water, and sulfosuccinic acid diester ammonium salt And 20 parts by mass of a 20% aqueous solution of trade name &quot; La Tempel S-180A &quot;, manufactured by Kao Corporation) was charged and the temperature in the reaction vessel was raised to 78 캜. To this, 0.5 part by mass of ammonium persulfate was added and kept for 1 hour. Thus, the seed latex of the first step was prepared. The hydrogen ion concentration of the seed latex was measured and found to be pH 1.8.

Next, a mixed solution of 3 parts by mass of methacrylic acid, 207 parts by mass of methyl methacrylate, 190 parts by mass of butyl acrylate, and 1.0 part by mass of? -Methacryloxypropyltrimethoxysilane, 300 parts by mass of water, 20 parts by mass of a 20% aqueous solution of ammonium salt ("Latem S-180A", manufactured by Kao Corporation) and 1.0 part by mass of ammonium persulfate were added dropwise to the reaction vessel from the dropping bath over 3 hours. During the dropwise addition, the temperature in the reaction vessel was maintained at 80 占 폚. After completion of dropwise addition, the temperature in the reaction vessel was maintained at 85 캜 for 6 hours and then cooled to room temperature. The hydrogen ion concentration of this reaction product was measured to be 2.8. A 25% aqueous ammonia solution was added to the reaction mixture to adjust the pH to 8, and the mixture was filtered through a wire mesh of 100 mesh to obtain an emulsion.

The obtained emulsion had a solid content of 44% by mass and a volume average particle diameter of 0.095 占 퐉.

Further, except that "VGCF-X" was used instead of "VGCF" as the carbon nanofiber, and the organic emulsion was added so that the solid content in the organic emulsion was 5 parts by mass with respect to 100 parts by mass of the carbon nanofiber The carbon nanofiber agglomerates were obtained in the same manner as in Example 1.

The obtained carbon nanofiber agglomerates were used as resin compositions in the following manner, and their physical properties were evaluated. First, a polyamide resin composition containing 95 mass% of a polyamide and 5 mass% of a carbon nanofiber aggregate was prepared and evaluated for dispersibility in accordance with the above-described method. Next, a polyamide resin composition containing 97.5% by mass of polyamide and 2.5% by mass of carbon nanofiber aggregates was prepared and used for conductivity evaluation in accordance with the above-described method.

[Example 17]

A polyamide resin composition containing 95 mass% of a polyamide and 5 mass% of a carbon nanofiber aggregate obtained in Example 1 was produced in accordance with the above-described method, and a tensile fracture strength at 23 占 폚 and a tensile strength at 23 占 폚 The elongation at break was obtained.

[Example 18]

A polyethylene resin composition containing 95 mass% of polyethylene and 5 mass% of the carbon nanofiber aggregate obtained in Example 1 was produced in accordance with the above-described method, and the tensile fracture strength at 23 deg. C and the tensile fracture elongation at 23 deg. Respectively.

[Example 19]

A polyamide resin composition containing 95 mass% of a polyamide and 5 mass% of a carbon nanofiber aggregate obtained in Example 2 was produced in accordance with the above-described method, and a tensile fracture strength at 23 占 폚 and a tensile strength at 23 占 폚 The elongation at break was obtained.

[Example 20]

A polyethylene resin composition containing 95 mass% of polyethylene and 5 mass% of the carbon nanofiber aggregates obtained in Example 2 was produced in accordance with the above-described method, and the tensile rupture strength at 23 占 폚 and the tensile rupture elongation at 23 占 폚 Respectively.

[Example 21]

A polyamide resin composition containing 95 mass% of polyamide and 5 mass% of carbon nanofiber aggregate obtained in Example 3 was produced in accordance with the above-described method, and the tensile fracture strength at 23 占 폚 and the tensile breaking strength at 23 占 폚 The elongation at break was obtained.

[Example 22]

A polyethylene resin composition containing 95 mass% of polyethylene and 5 mass% of carbon nanofiber aggregates obtained in Example 3 was produced in accordance with the above-described method, and a tensile rupture strength at 23 占 폚 and a tensile rupture elongation at 23 占 폚 Respectively.

[Example 23]

A polyamide resin composition containing 95 mass% of a polyamide and 5 mass% of a carbon nanofiber aggregate obtained in Example 4 was produced in accordance with the above-described method, and a tensile fracture strength at 23 占 폚 and a tensile strength at 23 占 폚 The elongation at break was obtained.

[Example 24]

A polypropylene resin composition containing 95 mass% of polypropylene and 5 mass% of the carbon nanofiber aggregate obtained in Example 4 was produced in accordance with the above-described method, and the tensile fracture strength at 23 占 폚 and the tensile strength at 23 占 폚 The elongation at break was obtained.

[Example 25]

A polyamide resin composition containing 95 mass% of a polyamide and 5 mass% of a carbon nanofiber aggregate obtained in Example 5 was produced in accordance with the above-described method, and a tensile fracture strength at 23 占 폚 and a tensile strength at 23 占 폚 The elongation at break was obtained.

[Example 26]

A polyethylene resin composition containing 95 mass% of polyethylene and 5 mass% of the carbon nanofiber aggregate obtained in Example 5 was produced in accordance with the above-described method, and the tensile fracture strength at 23 deg. C and the tensile fracture elongation at 23 deg. Respectively.

[Example 27]

A polyamide resin composition containing 95 mass% of polyamide and 5 mass% of carbon nanofiber aggregates obtained in Example 6 was produced in accordance with the above-described method, and the tensile fracture strength at 23 占 폚 and the tensile strength at 23 占 폚 The elongation at break was obtained.

[Example 28]

A polyethylene resin composition containing 95 mass% of polyethylene and 5 mass% of carbon nanofiber aggregates obtained in Example 6 was produced in accordance with the above-described method, and the tensile fracture strength at 23 占 폚 and the tensile fracture elongation at 23 占 폚 Respectively.

[Example 29]

A polyamide resin composition containing 95 mass% of a polyamide and 5 mass% of a carbon nanofiber aggregate obtained in Example 7 was produced in accordance with the above-described method, and a tensile fracture strength at 23 占 폚 and a tensile strength at 23 占 폚 The elongation at break was obtained.

[Example 30]

A polypropylene resin composition containing 95 mass% of polypropylene and 5 mass% of the carbon nanofiber aggregate obtained in Example 7 was produced in accordance with the above-described method, and a tensile fracture strength at 23 占 폚 and a tensile strength at 23 占 폚 The elongation at break was obtained.

[Example 31]

A polyamide resin composition containing 95 mass% of a polyamide and 5 mass% of a carbon nanofiber aggregate obtained in Example 8 was produced in accordance with the above-described method, and a tensile fracture strength at 23 占 폚 and a tensile strength at 23 占 폚 The elongation at break was obtained.

[Example 32]

A polypropylene resin composition containing 95 mass% of polypropylene and 5 mass% of the carbon nanofiber aggregate obtained in Example 8 was produced in accordance with the above-described method, and a tensile fracture strength at 23 占 폚 and a tensile strength at 23 占 폚 The elongation at break was obtained.

[Example 33]

A polyamide resin composition containing 95 mass% of a polyamide and 5 mass% of a carbon nanofiber aggregate obtained in Example 9 was produced in accordance with the above-described method, and a tensile fracture strength at 23 占 폚 and a tensile strength at 23 占 폚 The elongation at break was obtained.

[Example 34]

A polypropylene resin composition containing 95 mass% of polypropylene and 5 mass% of the carbon nanofiber aggregate obtained in Example 9 was produced in accordance with the above-described method, and a tensile fracture strength at 23 占 폚 and a tensile strength at 23 占 폚 The elongation at break was obtained.

[Example 35]

A polyamide resin composition containing 95 mass% of a polyamide and 5 mass% of a carbon nanofiber aggregate obtained in Example 10 was produced in accordance with the above-described method, and a tensile fracture strength at 23 占 폚 and a tensile strength at 23 占 폚 The elongation at break was obtained.

[Example 36]

A polypropylene resin composition containing 95 mass% of polypropylene and 5 mass% of the carbon nanofiber aggregate obtained in Example 10 was produced in accordance with the above-described method, and the tensile fracture strength at 23 占 폚 and the tensile strength at 23 占 폚 The elongation at break was obtained.

[Example 37]

A polyamide resin composition containing 95 mass% of a polyamide and 5 mass% of a carbon nanofiber aggregate obtained in Example 11 was produced in accordance with the above-described method, and a tensile fracture strength at 23 占 폚 and a tensile strength at 23 占 폚 The elongation at break was obtained.

[Example 38]

A polypropylene resin composition containing 95 mass% of polypropylene and 5 mass% of carbon nanofiber aggregates obtained in Example 11 was produced in accordance with the above-described method, and a tensile fracture strength at 23 占 폚 and a tensile strength at 23 占 폚 The elongation at break was obtained.

[Example 39]

A polyamide resin composition containing 95 mass% of a polyamide and 5 mass% of a carbon nanofiber aggregate obtained in Example 12 was produced in accordance with the above-described method, and a tensile fracture strength at 23 占 폚 and a tensile strength at 23 占 폚 The elongation at break was obtained.

[Example 40]

A polyethylene resin composition containing 95 mass% of polyethylene and 5 mass% of the carbon nanofiber aggregates obtained in Example 12 was produced in accordance with the above-described method, and the tensile fracture strength at 23 占 폚 and the tensile fracture elongation at 23 占 폚 Respectively.

[Example 41]

A polyamide resin composition containing 95 mass% of a polyamide and 5 mass% of a carbon nanofiber aggregate obtained in Example 13 was produced in accordance with the above-described method, and a tensile fracture strength at 23 占 폚 and a tensile strength at 23 占 폚 The elongation at break was obtained.

[Example 42]

A polyethylene resin composition containing 95 mass% of polyethylene and 5 mass% of the carbon nanofiber aggregate obtained in Example 13 was produced in accordance with the above-described method. The tensile rupture strength at 23 占 폚 and the tensile rupture elongation at 23 占 폚 Respectively.

[Example 43]

A polyamide resin composition containing 95 mass% of a polyamide and 5 mass% of a carbon nanofiber aggregate obtained in Example 14 was produced in accordance with the above-described method, and a tensile fracture strength at 23 占 폚 and a tensile strength at 23 占 폚 The elongation at break was obtained.

[Example 44]

A polyamide resin composition containing 95 mass% of a polyamide and 5 mass% of a carbon nanofiber aggregate obtained in Example 15 was produced in accordance with the above-described method, and a tensile breaking strength at 23 占 폚 and a tensile strength at 23 占 폚 The elongation at break was obtained.

[Example 45]

A polyamide resin composition containing 95 mass% of a polyamide and 5 mass% of a carbon nanofiber aggregate obtained in Example 16 was produced in accordance with the above-described method, and a tensile fracture strength at 23 占 폚 and a tensile strength at 23 占 폚 The elongation at break was obtained.

[Example 46]

A master batch of a polyamide resin composition containing 20 mass% of the carbon nanofiber agglomerates obtained in Example 7 was prepared, and pellets of a polyamide resin composition containing 5 mass% of carbon nanofiber agglomerates were prepared. The carbon nano aggregate prepared in Example 7 and the polyamide were kneaded at a temperature of 300 DEG C and a rotation speed of 200 rpm using "KZW15" (screw diameter 15 mm, L / D ratio 45) manufactured by Techno Bell, And this was water-cooled and cut to obtain a polyamide master batch containing 20 mass% of carbon nanofiber agglomerates. The obtained master batch and polyamide pellets (PA: Leona 1300S, manufactured by Asahi Chemical Industry Co., Ltd.) were blended so that the ratio of the carbon nano aggregates was 5 mass%, and the mixture was thoroughly mixed in a polyethylene bag. This was kneaded using "KZW15" manufactured by Techno Bell Co., Ltd., at a temperature of 280 ° C. at a rotation speed of 500 rpm to obtain a strand. The strand was water-cooled and cut to obtain a polyamide resin composition containing 5 mass% of carbon nanofiber aggregates Pellets were obtained. Then, the dispersibility evaluation and the L / D ratio of the carbon nanofibers in the polyamide resin composition were measured.

[Example 47]

A master batch of the polyamide resin composition containing 20 mass% of the carbon nanofiber agglomerates obtained in Example 8 was produced in accordance with the same method as in Example 46, and a polyamide resin containing 5 mass% of carbon nanofiber agglomerates Pellets of the resin composition were prepared. Then, the dispersibility evaluation and the L / D ratio of the carbon nanofibers in the polyamide resin composition were measured.

[Example 48]

A master batch of a polyamide resin composition containing 20 mass% of the carbon nanofiber agglomerates obtained in Example 11 was prepared in accordance with the same method as in Example 46, and from this, a polyamide containing 5 mass% of carbon nanofiber agglomerates Pellets of the resin composition were prepared. Then, the dispersibility evaluation and the L / D ratio of the carbon nanofibers in the polyamide resin composition were measured.

&Lt; Comparative Example 1 &

10 g of carbon nanofibers (trade name "VGCF-X") was placed in a 1 liter Nasflask, and 40 mass% of water was added to the carbon nanofibers to obtain a mixture. The resulting mixture was degassed in vacuo at a temperature of about 80 캜 for 10 minutes using a separator and then pulverized with a mortar to obtain carbon nanofiber agglomerates.

The obtained carbon nanofiber agglomerates were used as resin compositions in the following manner, and their physical properties were evaluated.

First, a polyamide resin composition containing 95 mass% of polyamide and 5 mass% of carbon nanofiber aggregate was produced in accordance with the above-described method. Similarly, a polyethylene resin composition containing 95 mass% of polyethylene and 5 mass% of carbon nanofiber aggregates was prepared. These resin compositions were used for evaluation of dispersibility.

Next, a polyamide resin composition containing 97.5% by mass of polyamide and 2.5% by mass of carbon nanofiber aggregate was produced in accordance with the above-described method. This resin composition was used for conductivity evaluation.

&Lt; Comparative Example 2 &

10 g of carbon nanofiber (trade name "VGCF-X") was put into a 1 liter Nasflask and 10 mass% ethanol solution of polyethylene glycol 6000 (PEG, reagent) was added at a ratio of 50 mass% to the carbon nanofibers To obtain a mixture. The resulting mixture was degassed in vacuo at a temperature of about 80 캜 for 10 minutes using a separator and then pulverized with a mortar to obtain carbon nanofiber agglomerates.

The obtained carbon nanofiber agglomerates were used as resin compositions in the following manner, and their physical properties were evaluated.

First, a polyamide resin composition containing 95 mass% of polyamide and 5 mass% of carbon nanofiber aggregate was produced in accordance with the above-described method. Similarly, a polyethylene resin composition containing 95 mass% of polyethylene and 5 mass% of carbon nanofiber aggregates was prepared. These resin compositions were used for evaluation of dispersibility.

Next, a polyamide resin composition containing 97.5% by mass of polyamide and 2.5% by mass of carbon nanofiber aggregate was produced in accordance with the above-described method. This resin composition was used for conductivity evaluation.

[Comparative Example 3]

, 10 g of a carbon nanofiber aggregate (trade name &quot; VGCF-X &quot;), 1 g of acid-modified SEBS (trade name &quot; Tarftec M1913 &quot;, trade name; manufactured by Asahi Chemical Industry Co., Ltd., maleic anhydride- modified SEBS) and 300 ml of toluene And the mixture was introduced into a Naris flask. The resulting mixture was vacuum degassed at a temperature of 80 캜 using an expander, and then pulverized with a mortar to obtain carbon nanofiber agglomerates.

The obtained carbon nanofiber agglomerates were used as resin compositions in the following manner, and their physical properties were evaluated.

First, a polyamide resin composition containing 95 mass% of polyamide and 5 mass% of carbon nanofiber aggregate was produced in accordance with the above-described method. This resin composition was used for evaluation of dispersibility.

Next, a polyamide resin composition containing 97.5% by mass of polyamide and 2.5% by mass of carbon nanofiber aggregate was produced in accordance with the above-described method. This resin composition was used for conductivity evaluation.

[Comparative Example 4]

10 g of the carbon nanofiber agglomerate and 300 ml of ethanol were put into a 2 L flask and were vacuum degassed at about 60 캜 using an expander to distill off the solvent. This was filled in a circular mold (100 mm in diameter, 1 mm in thickness) and press-molded to obtain a molded article. The obtained molded body was pulverized with a mortar to obtain a carbon nanofiber agglomerate.

The obtained carbon nanofiber agglomerates were used as resin compositions in the following manner, and their physical properties were evaluated.

First, a polyamide resin composition containing 95 mass% of polyamide and 5 mass% of carbon nanofiber aggregate was produced in accordance with the above-described method. Similarly, a polypropylene resin composition containing 95 mass% of polypropylene and 5 mass% of carbon nanofiber aggregate was prepared. These resin compositions were used for evaluation of dispersibility.

Next, a polyamide resin composition containing 97.5% by mass of polyamide and 2.5% by mass of carbon nanofiber aggregate was produced in accordance with the above-described method. This resin composition was used for conductivity evaluation.

[Comparative Example 5]

A polyamide resin composition containing 95 mass% of a polyamide and 5 mass% of a carbon nanofiber aggregate obtained in Comparative Example 1 was produced in accordance with the above-described method, and a tensile fracture strength at 23 占 폚 and a tensile strength at 23 占 폚 The elongation at break was obtained.

[Comparative Example 6]

A polyethylene resin composition containing 95 mass% of polyethylene and 5 mass% of the carbon nanofiber aggregates obtained in Comparative Example 1 was produced in accordance with the above-described method, and the tensile fracture strength at 23 占 폚 and the tensile fracture elongation at 23 占 폚 Respectively.

[Comparative Example 7]

A polyamide resin composition containing 95 mass% of a polyamide and 5 mass% of a carbon nanofiber aggregate obtained in Comparative Example 2 was produced in accordance with the above-described method, and a tensile fracture strength at 23 占 폚 and a tensile strength at 23 占 폚 The elongation at break was obtained.

[Comparative Example 8]

A polyethylene resin composition containing 95 mass% of polyethylene and 5 mass% of the carbon nanofiber aggregates obtained in Comparative Example 2 was produced in accordance with the above-described method, and the tensile fracture strength at 23 占 폚 and the tensile fracture elongation at 23 占 폚 Respectively.

[Comparative Example 9]

A polyamide resin composition containing 95 mass% of a polyamide and 5 mass% of a carbon nanofiber aggregate obtained in Comparative Example 3 was produced in accordance with the above-described method, and a tensile fracture strength at 23 占 폚 and a tensile strength at 23 占 폚 The elongation at break was obtained.

[Comparative Example 10]

A polyamide resin composition containing 95 mass% of a polyamide and 5 mass% of a carbon nanofiber aggregate obtained in Comparative Example 4 was produced in accordance with the above-described method, and a tensile fracture strength at 23 占 폚 and a tensile strength at 23 占 폚 The elongation at break was obtained.

[Comparative Example 11]

A polypropylene resin composition containing 95% by mass of polypropylene and 5% by mass of the carbon nanofiber aggregate obtained in Comparative Example 4 was produced in accordance with the above-described method, and a tensile fracture strength at 23 占 폚 and a tensile strength at 23 占 폚 The elongation at break was obtained.

The physical properties and evaluation results of the respective examples and comparative examples are shown in Tables 1 to 6 below.

From the above, it was confirmed that the carbon nanofiber aggregates of the respective Examples were able to suppress scattering, and were also excellent in dispersibility and filling property with respect to the thermoplastic resin. Further, it was also confirmed that the resin composition can be made excellent in electrical characteristics and the like.

The present application is based on Japanese Patent Application (Japanese Patent Application No. 2011-225379) filed on October 12, 2011, and filed with the Japanese Patent Office, the contents of which are incorporated herein by reference.

Industrial availability

The carbon nanofiber agglomerates of the present invention are easier to mix and disperse in the thermoplastic resin than those of the conventional ones, and can improve the physical properties of various thermoplastic resins and have industrial applicability in a wide range of fields.

Claims (10)

The maximum pore volume P1 (cm3 / g) at a pore diameter of not less than 2,500 nm and not more than 100,000 nm and the maximum pore volume P2 (cm3 / g) at a pore diameter of not less than 6 nm and less than 2,500 nm in pore distribution data measured by mercury porosimetry (Cm &lt; 3 &gt; / g) satisfy the relations of the following formulas (1) and (2).
0.01? P1? 1 (1)
0 &lt; P1 / P2? 3.3 (2) The method according to claim 1,
Carbon nanofiber aggregates having a three-dimensionally assembled structure as an interstices structure of carbon nanofibers constituting the aggregates of carbon nanofibers. 3. The method according to claim 1 or 2,
Wherein the pore distribution data measured by the mercury porosimeter includes a cumulative pore volume Q1 (cm3 / g) at a pore diameter of from 2,500 to 100,000 nm and a cumulative pore volume at a pore diameter of from 6 to 2500 nm And Q2 (cm &lt; 3 &gt; / g) satisfy the relation of the following formula (3).
0.75? Q2 / (Q1 + Q2) <1 (3) 3. The method according to claim 1 or 2,
(A) at least one member selected from the group consisting of carbon nanofibers, (B) a modified rosin, a styrene resin, an olefin resin, and an acrylic acid resin,
A carbon nanofiber aggregate having a content ratio of carbon nanofiber aggregates having a particle size passing through a sieve having a nominal scale size defined by JIS Z8801-1 of more than 0.3 mm and not more than 4.75 mm of not less than 90% by mass. 5. The method of claim 4,
100 parts by mass of the component (A)
0.1 to 50 parts by mass of the component (B)
(C) 0.01 to 30 parts by mass of a surfactant
Carbon nanofiber aggregate. 6. The method of claim 5,
Wherein the content of the component (B) relative to 100 parts by mass of the component (A) is 0.1 to 40 parts by mass. A thermoplastic resin composition comprising a thermoplastic resin and the carbon nanofiber aggregate according to any one of claims 1 to 3. 8. The method of claim 7,
Wherein the carbon nanofibers in the thermoplastic resin composition have an L / D ratio of 50 or more. 9. The method of claim 8,
10 pellets molded from the above thermoplastic resin composition were cut out by a microtome into pellets and observed with a light microscope (400 times) at a viewing angle of 200 占 퐉 占 200 占 퐉, the carbon observed in the observation region of the optical microscope Wherein the major axes of the nanofiber aggregates are all less than 10 占 퐉. A process for producing a thermoplastic resin composition comprising a step of melt-kneading a thermoplastic resin and the carbon nanofiber aggregate according to claim 1 or 2 to obtain a thermoplastic resin composition.

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